This invention relates to an auxiliary lens attachment for releasable attachment of auxiliary lenses such as sun shades to prescription eyeglasses.
Conventional mounting mechanisms for releasably attaching auxiliary lenses to eyeglasses either attach to the bridge of the eyeglasses, the lens frame of the eyeglasses, or the lenses of the eyeglasses. Mounting arrangements for releasably attaching auxiliary lenses to eyeglasses typically add significant structural features to the auxiliary lenses which are often unattractive. Furthermore, they may partially obstruct the view of the wearer. Some mounting mechanisms attach the auxiliary lenses to eyeglasses in a manner that results in gaps between the auxiliary lenses and the eyeglasses lenses which may distract or distort the view of the wearer.
One type of mounting mechanism utilizes a clamp assembly attached to the bridge structure connecting the auxiliary lenses. The clamp assembly includes pairs of opposing clip members which are spring loaded toward each other so as to frictionally retain therebetween the bridge and/or the lenses of the eyeglasses to which the auxiliary lenses are to be attached. While these clamp mechanisms have the advantage of potentially being able to fit a variety of different eyeglasses styles, the attachment may be insecure in some cases while in others the clamp mechanism parts may tightly engage the lenses of the eyeglasses, potentially scratching the lenses.
Another type of auxiliary lens mounting mechanism for use with eyeglasses includes a frame with means for holding a pair of auxiliary lenses with greater curvature in the horizontal plane than the curvature of the lenses of the eyeglasses. The frame includes a generally U-shaped attachment member with resilient prongs configured to extend over the lens frames of the eyeglasses and releasably engage cooperative grooves on the rear face of the eyeglasses frame to effect a snap-fit connection with the eyeglasses frame and urge the auxiliary lenses against the upper outer edges of the eyeglasses frame. Such mounting mechanism provides a simple, secure attachment, but has the disadvantage that it must be custom made to fit a particular size and style of eyeglasses frame which is specifically designed to accept the mounting mechanism.
Another peripheral type mounting mechanism designed to engage the eyeglasses lens frame members includes a number of resilient prongs fixed along a frame of the auxiliary lenses in a manner that the prongs snap onto the frame members of the eyeglasses. This type of mounting mechanism has the disadvantage that it must exactly fit the size and shape of the eyeglasses frame, requiring it to be custom made to fit a particular size and style of eyeglasses.
Accordingly, it is desirable to provide an auxiliary lens attachment that is capable of releasable connection to a variety of standard eyeglasses styles and sizes, is aesthetically pleasing in appearance, and that will securely retain the auxiliary lenses in desired position without obstructing or distorting the view of the wearer or damaging the lenses of the eyeglasses.